Voice dialing systems require speech recognition capabilities to process voice commands. Speech recognition capabilities may be implemented in a mobile phone to allow a user to easily dial a phone number. For example, the user may initiate a call to a contact in an address book on the mobile phone by saying the name of the contact. Speech recognition allows the voice dialing system to process the name and automatically dial the correct number.
In order for the voice dialing system to correctly identify the correct number to dial, the user must say the name of the contact clearly. For example, distortion, mispronunciation, and background noise may cause the voice dialing system to misunderstand the intended contact. Therefore, voice dialing systems may implement a system wherein a confidence value is assigned to the voice input of the user. In other words, the confidence value indicates the presumed accuracy of the intended contact as determined by the voice dialing system. A low confidence value may indicate that further measures are necessary in order to dial the correct number. For example, the voice dialing system may require the user to restate the name of the intended contact. Of course, in a particular implementation, the role of the confidence value might be played by a measure whose value would be low when speech is well-recognized, and high when misunderstanding is probable. This could be called an “uncertainty measure.” A high value of the uncertainty measure might indicate that further measures are necessary to dial the correct number. Despite the superficial differences between the two types of measures, they play the same kind of role in the system.